1. Field of the Invention
The instant invention relates to bioefficaciously enhanced organophosphorous insecticidal formulations comprising the active and low volatile organic compound (low VOC) compositions; processes for preparing same; and methods of use.
2. Technology Description
Insecticides, miticides, aphicides, fungicides, bacteriocides, acaricides, nematicides (hereinafter these pesticides will be generically referred to for conciseness as "insecticides" as the term "insecticidally" will similarly represent generically miticidally, nematicidally, etc.) continue to be a group of products of immense agricultural and economic importance. Insecticides are expected to display ideal properties of a wide array including broad-spectrum activity concomitant with safety to beneficial insects, low mammalian and fish toxicity, and sufficiently long residual action yet with insignificant, harmless residue levels. In keeping with the above goals, it is desirable to utilize the minimum amount of insecticide necessary to achieve the required results. Therefore, formulation adjuvants that enhance the bioefficacy of the active and thus result in lower effective delivery amounts of the active to a locus are much sought after.
Many, if not most, insecticidal compounds are solid materials which have very low solubility in water. As a result, formulators are constantly using their ingenuity to find means for preparing these materials in stable formulations that can deliver maximum loading of active ingredient per unit volume to the end-user.
The most straight-forward approach to preparing concentrated liquid formulations with agrochemical actives, especially insecticides having limited aqueous solubility, has been through the use of aromatic organic solvent systems. In such systems, aromatic organic solvents such as xylene or kerosene are used to solubilize the pesticidal compound of interest.
Commonly, surfactants are also added to the insecticide-solvent compositions to form emulsions. The surfactant-emulsifiers interact with the insecticides in a number of ways both before and during actual use, i.e., application to the locus. The surfactants, often a pair of nonionic and anionic surfactants, can initially disperse and/or emulsify the insecticide in the solvent or in an inert carrier media and may also act as spreader, sticker, stabilizer, wetting agent, and defoamer. The surfactant composition may affect the rate of drying of a droplet on a surface and the nature of a residue liquid or crystal.
The presence of the volatile organic compounds in these formulations, together with the surfactants, enable stable emulsifiable insecticidal concentrates (EC's) to be prepared. Although such EC formulations have played and continue to play a major role in the insecticidal market, they have a significant drawback in that the formulations are commonly based on the use of considerable quantities of highly volatile organic compounds (high VOC's). These high VOC's create both toxicological and ecotoxicological problems. As a result, many government agencies such as the United States Environmental Protection Agency and the European Economic Community Council are proposing legislation and many countries such as Germany and Canada are now requiring eco-labeling of formulations which contain high VOC's.
Thus, to reduce not only the deleterious effects upon the environment, but also the potential for hazardous worker exposure situations, especially in closed environments such as greenhouses, agricultural/chemical manufacturers and formulators continually seek ways to deliver highly loaded, stable insecticidal formulations to the end-user with significantly reduced levels of high VOC's and preferably without their presence.
To avoid the use of high VOC's in certain pesticidal formulations and to obtain slightly increased pesticidal loadings, Lubetzky, et al. in EP publication numbers 669,078 and 670,113 have disclosed the use of rosin and rosin derivatives that are insoluble in water to "plasticize" certain pesticides and thus to prepare pesticidal emulsions in water (EW's) and emulsifiable concentrates (EC's).
Applicants, in copending Provisional Application Ser. No. 60/070,101 filed Dec. 30, 1997, the disclosure of which is hereby incorporated by reference, relates to the discovery of extremely stable, highly loaded water soluble, low VOC pesticidal emulsion concentrates comprising a) a pesticide having a melting point of 110.degree. C. or less; b) an alkoxylated fatty acid and rosin acid composition having from greater than 25 to about 60 weight percent alkoxylated rosin acids and from about 40 to less than 75 weight percent alkoxylated fatty acids with about 9 to 20 alkoxy moieties per molecule of acid; and c) at least one nonionic surfactant. It was discovered that the aforedescribed ethoxylated acid compositions possess very unique solvent characteristics with respect to certain relatively water insoluble pesticides.